Walking into the GMAT without learning formal
reasoning is like walking into a used car lot without knowing anything
about cars. You need to know the common flaws or you won't be able to
Note that some of these logical error types won't
appear on the GMAT, but learning how to think logically and pull out
assumptions will help you get a higher score and will also help you on the AWA
Analysis of Argument section.
You don't have to memorize every logical fallacy with its formal Latin name, but you do need to get a general idea about what fallacies are and how to spot them.